Previous research has established a link between genetic mutations in the BRCA1 and BRCA2 genes to an increased risk of developing ovarian, fallopian tube or peritoneal cancer in women. A recent publication documents the ...

Evolutionary geneticists date events using the number of mutations that have accumulated since they occurred. For instance, they date the spilt time between humans and chimps by dividing the number of genetic differences ...

Columbia University Medical Center (CUMC) and University of Iowa scientists have used a new gene-editing technology called CRISPR, to repair a genetic mutation responsible for retinitis pigmentosa (RP), an inherited condition ...

No autism is alike. This is also true of most mental disorders. "We now understand that each gene mutation has a specific effect, which adds to other effects to draw a unique picture of the disease in each patient," said ...

Each year approximately 1 in 1,000 pregnant women will experience peripartum cardiomyopathy, an uncommon form of often severe heart failure that occurs in the final month of pregnancy or up to five months following delivery. ...

Researchers have used CRISPR to treat an adult mouse model of Duchenne muscular dystrophy. This marks the first time that CRISPR has successfully treated a genetic disease inside a fully developed living mammal with a strategy ...

(MedicalXpress)—A new technique developed by a team of researchers affiliated with a number of facilities in China allows medical practitioners involved in IVF treatment to more easily weed out embryos with genetic defects ...

Mutation

In biology, mutations are changes to the nucleotide sequence of the genetic material of an organism. Mutations can be caused by copying errors in the genetic material during cell division, by exposure to ultraviolet or ionizing radiation, chemical mutagens, or viruses, or can be induced by the organism itself, by cellular processes such as hypermutation. In multicellular organisms with dedicated reproductive cells, mutations can be subdivided into germ line mutations, which can be passed on to descendants through the reproductive cells, and somatic mutations, which involve cells outside the dedicated reproductive group and which are not usually transmitted to descendants. If the organism can reproduce asexually through mechanisms such as cuttings or budding the distinction can become blurred. For example, plants can sometimes transmit somatic mutations to their descendants asexually or sexually where flower buds develop in somatically mutated parts of plants. A new mutation that was not inherited from either parent is called a de novo mutation. The source of the mutation is unrelated to the consequence, although the consequences are related to which cells were mutated.

Mutations create variation within the gene pool. Less favorable (or deleterious) mutations can be reduced in frequency in the gene pool by natural selection, while more favorable (beneficial or advantageous) mutations may accumulate and result in adaptive evolutionary changes. For example, a butterfly may produce offspring with new mutations. The majority of these mutations will have no effect; but one might change the color of one of the butterfly's offspring, making it harder (or easier) for predators to see. If this color change is advantageous, the chance of this butterfly surviving and producing its own offspring are a little better, and over time the number of butterflies with this mutation may form a larger percentage of the population.

Neutral mutations are defined as mutations whose effects do not influence the fitness of an individual. These can accumulate over time due to genetic drift. It is believed that the overwhelming majority of mutations have no significant effect on an organism's fitness. Also, DNA repair mechanisms are able to mend most changes before they become permanent mutations, and many organisms have mechanisms for eliminating otherwise permanently mutated somatic cells.

Mutation is generally accepted by the scientific community as the mechanism upon which natural selection acts, providing the advantageous new traits that survive and multiply in offspring or disadvantageous traits that die out with weaker organisms.